Hinges of the type permitting a limited relative angular separation between their plates, generally less than 90.degree., are well known in the art. Such hinges have as one use, the interconnection of the support and backing of an easel-type picture frame and are thus generally referred to as easel hinges. Generally such easel hinges utilize a separate hinge pin to assemble and hold the opposed hinge plates in operative position. Examples of such easel hinges are found in U.S. Pat. No. 139,290 dated May 27, 1873; U.S. Pat. No. 1,501,013 dated July 8, 1924; and U.S. Pat. No. 2,811,741 dated Nov. 5, 1957. The use of such pins, in addition to adding to the physical cost of the hinge, does not lend itself to automatic machine assembly, and generally requires hand assembly and accordingly further increases the cost of such type hinges.
Easel hinges which eliminate such separate pin structure are known as indicated by that shown in U.S. Pat. No. 3,080,603 dated Mar. 12, 1963. Such hinge structures however are generally of overly complex configuration.
The need thus exists for a simple, low cost, easel hinge construction which can be readily made and assembled on automatic machinery and which does not utilize either a separate hinge pin or complex hinge or stop mechanisms.